Abstract: An apparatus having both a resonator and an inductor fabricated on a single substrate and a method of fabricating the apparatus are disclosed. The apparatus includes a resonator and an inductor that is connected to the resonator. Both the resonator and the inductor are fabricated over their respective cavities to produce a high Q-factor filter circuit.

Abstract: A method for fabricating a resonator, and in particular, a thin film bulk acoustic resonator (FBAR), and a resonator embodying the method are disclosed. An FBAR is fabricated on a substrate by mass loading piezoelectric (PZ) layer between two electrodes. For a substrate having multiple resonators, only selected resonator is mass loaded to provide resonators having different resonance frequencies on the same substrate.

Abstract: In an array of acoustic resonators, the effective coupling coefficient of first and second filters are individually tailored in order to achieve desired frequency responses. In a duplexer embodiment, the effective coupling coefficient of a transmit band-pass filter is lower than the effective coupling coefficient of a receive band-pass filter of the same duplexer. In one embodiment, the tailoring of the coefficients is achieved by varying the ratio of the thickness of a piezoelectric layer to the total thickness of electrode layers. For example, the total thickness of the electrode layers of the transmit filter may be in the range of 1.2 to 2.8 times the total thickness of the electrode layers of the receive filter. In another embodiment, the coefficient tailoring is achieved by forming a capacitor in parallel with an acoustic resonator within the filter for which the effective coupling coefficient is to be degraded.

Abstract: In an array of acoustic resonators, the effective coupling coefficient of first and second filters are individually tailored in order to achieve desired frequency responses. In a duplexer embodiment, the effective coupling coefficient of a transmit band-pass filter is lower than the effective coupling coefficient of a receive band-pass filter of the same duplexer. In one embodiment, the tailoring of the coefficients is achieved by varying the ratio of the thickness of a piezoelectric layer to the total thickness of electrode layers. For example, the total thickness of the electrode layers of the transmit filter may be in the range of 1.2 to 2.8 times the total thickness of the electrode layers of the receive filter. In another embodiment, the coefficient tailoring is achieved by forming a capacitor in parallel with an acoustic resonator within the filter for which the effective coupling coefficient is to be degraded.

Abstract: A method for fabricating a resonator, and in particular, a thin film bulk acoustic resonator (FBAR), and a resonator embodying the method are disclosed. An FBAR is fabricated on a substrate by introducing a mass loading electrode to a bottom electrode layer. For a substrate having multiple resonators, mass loading bottom electrode is introduced for only selected resonator to provide resonators having different resonance frequencies on the same substrate.

Abstract: A filter, such as a transmit filter of a duplexer, includes an array of acoustic resonators that cooperate to establish an asymmetrically shaped filter response over a target frequency passband. The acoustic resonators are preferably film bulk acoustic resonators (FBARs). The filter response defines an insertion loss profile in which a minimum insertion loss within the target passband is located at or near a first end of the frequency passband, while the maximum insertion loss is located at or near the opposite end of the frequency passband. In the transmit filter embodiment, the minimum insertion loss is at or near the high frequency end of the filter response, which is tailored by selectively locating poles and zeros of the array of FBARs.

Abstract: A method for fabricating a resonator, and in particular, a thin film bulk acoustic resonator (FBAR), and a resonator embodying the method are disclosed. An FBAR is fabricating on a substrate by introducing a mass loading electrode to a bottom electrode layer. For a substrate having multiple resonators, mass loading bottom electrode is introduced for only selected resonator to provide resonators having different resonance frequencies on the same substrate.

Abstract: A method for fabricating a resonator, and in particular, a thin film bulk acoustic resonator (FBAR), and a resonator embodying the method are disclosed. An FBAR is fabricated on a substrate by reducing mass from a top electrode layer. For a substrate having multiple resonators, mass is reduced from only selected resonator to provide resonators having different resonance frequencies on the same substrate.

Abstract: A method for fabricating a resonator, and in particular, a thin film bulk acoustic resonator (FBAR), and a resonator embodying the method are disclosed. A resonator is fabricated on a substrate, and its top electrode 56 is oxidized to form a oxide layer 58. For a substrate having multiple resonators, the top electrode 56 of only selected resonator is oxidized to provide resonators having different resonance frequencies on the same substrate.

Abstract: A method for fabricating an acoustic resonator, for example a Thin Film Bulk Acoustic Resonators (FBAR), on a substrate. A depression is etched and filled with sacrificial material. The FBAR is fabricated on the substrate spanning the depression, the FBAR having an etch hole. The depression may include etch channels in which case the FBAR may include etch holes aligned with the etch channels. A resonator resulting from the application of the technique is suspended in air and includes at least one etch hole and may include etch channels.

Abstract: A method for fabricating a resonator, and in particular, a thin film bulk acoustic resonator (FBAR), and a resonator embodying the method are disclosed. An FBAR is fabricated on a substrate by mass loading piezoelectric (PZ) layer between two electrodes. For a substrate having multiple resonators, only selected resonator is mass loaded to provide resonators having different resonance frequencies on the same substrate.

Abstract: A method for fabricating a resonator, and in particular, a thin film bulk acoustic resonator (FBAR), and a resonator embodying the method are disclosed. An FBAR is fabricated on a substrate by introducing a mass loading top electrode layer. For a substrate having multiple resonators, the top mass loading electrode layer is introduced for only selected resonator to provide resonators having different resonance frequencies on the same substrate.

Abstract: A method for fabricating a resonator, and in particular, a thin film bulk acoustic resonator (FBAR), and a resonator embodying the method are disclosed. The resonator is fabricated on a substrate by fabricating a bottom electrode layer and a piezoelectric (PZ) layer over the bottom electrode layer. A selected portion of the PZ layer is partially etched. Then, a top electrode is fabricated over the selected portion of the PZ layer.

Abstract: A filter, such as a transmit filter of a duplexer, includes an array of acoustic resonators that cooperate to establish an asymmetrically shaped filter response over a target frequency passband. The acoustic resonators are preferably film bulk acoustic resonators (FBARs). The filter response defines an insertion loss profile in which a minimum insertion loss within the target passband is located at or near a first end of the frequency passband, while the maximum insertion loss is located at or near the opposite end of the frequency passband. In the transmit filter embodiment, the minimum insertion loss is at or near the high frequency end of the filter response, which is tailored by selectively locating poles and zeros of the array of FBARs.

Abstract: A microcap wafer-level package is provided in which a micro device is connected to bonding pads on a base wafer. A peripheral pad on the base wafer encompasses the bonding pads and the micro device. A cap wafer has gaskets formed thereon using a thick photoresist semiconductor photolithographic process. Bonding pad gaskets match the perimeters of the bonding pads and a peripheral pad gasket matches the peripheral pad on the base wafer. Wells are located inside the perimeters of the bond pad gaskets and are formed to a predetermined depth in the cap wafer. The cap wafer is then placed over the base wafer to cold weld bond the gaskets to the pads and form a hermetically sealed volume between the bonding pad gaskets and the peripheral pad gasket. The cap wafer is then thinned below the predetermined depth until the wells become through holes that provide access to the bonding pads inside the package, but outside the hermetically sealed volume, for connecting wires from a micro device utilizing system.

Abstract: A bulk acoustic resonator having a high quality factor is formed on a substrate having a depression formed in a top surface of the substrate. The resonator includes a first electrode, a piezoelectric material and a second electrode. The first electrode is disposed on the top surface of the substrate and extends beyond the edges of the depression by a first distance to define a first region therebetween. The piezoelectric material is disposed on the top surface of the substrate and over the first electrode, and the second electrode is disposed on the piezoelectric material. The second electrode includes a portion that is located above the depression. The portion of the second electrode that is located over the depression has at least one edge that is offset from a corresponding edge of the depression by a second distance to define a second region therebetween. The first and second regions have different impedances, as a result of the different materials located in the two regions.

Abstract: A bulk acoustic resonator having a high quality factor is formed on a substrate having a depression formed in a top surface of the substrate. The resonator includes a first electrode, a piezoelectric material and a second electrode. The first electrode is disposed on the top surface of the substrate and extends beyond the edges of the depression by a first distance to define a first region therebetween. The piezoelectric material is disposed on the top surface of the substrate and over the first electrode, and the second electrode is disposed on the piezoelectric material. The second electrode includes a portion that is located above the depression. The portion of the second electrode that is located over the depression has at least one edge that is offset from a corresponding edge of the depression by a second distance to define a second region therebetween. The first and second regions have different impedances, as a result of the different materials located in the two regions.

Abstract: A device includes a die that contains a filter circuit. The filter is implemented using film bulk acoustic resonators. A package contains the die. The package includes a base portion. Signal paths are incorporated in the base portion. Solder joints attach the die to the base portion. The solder joints electrically connect pads on the die to the signal paths in the base portion. The solder joints do not include, and are used instead of, wire bonds.

Abstract: A filter formed of acoustic resonators, where each resonator has its own cavity and a bottom electrode that spans the entirety of the cavity, so that the bottom electrode has an unsupported interior region surrounded by supported peripheral regions. In the preferred embodiment, the cavity is formed by etching a depression into the substrate, filling the depression with a sacrificial material, depositing the piezoelectric and electrode layers that define an FBAR or SBAR, and then removing the sacrificial material from the depression. Also in the preferred embodiment, the sacrificial material is removed via release holes that are limited to the periphery of the depression. Preferably, the bottom electrode is the only electrode that spans the cavity, thereby limiting the formation of parasitic FBARs or SBARs. In one embodiment, the bottom electrode includes a serpentine edge that leaves a portion of one side of the cavity free of overlap by the bottom electrode, so that a top electrode may overlap this portion.

Abstract: A plurality of acoustic resonators are manufactured in a batch process by forming cavities in a substrate and filling the cavities with a sacrificial layer. An FBAR membrane comprising a bottom electrode, a piezoelectric layer, and a top electrode is formed over each cavity and the sacrificial layer. The substrate is then thinned and the substrate is separated into a plurality of dice using a scribe and break process. The sacrificial layer is then removed and the FBAR filter is mounted in a package with thermal vias being thermal communication with underside of the FBAR filter. The production method improves thermal properties by increasing the efficiency of heat dissipation from the FBAR filter. In addition, electromagnetic interference is decreased by reducing the distance between a primary current flowing over the surface of the FBAR filter and an image current flowing in a ground plane beneath the FBAR filter.